What is retroperitoneal fibrosis?

Extensive fibrotic encasement of the retroperitoneal tissues Diffuse desmoplastic involvement of the retroperitoneum may cause obstructive jaundice or small or large bowel obstruction Classic diagnostic triad : Bilateral hydronephrosis/ hydroureter Medial deviation of the ureters, Extrinsic ureteral compression at the L4–L5 level Ultrasound demonstrates hydronephrosis CT scan or magnetic resonance imaging shows fibrotic process and the classic diagnostic triad